Heat Flux Sensor Applications for Below-Grade Energy Studies

The use of heat flux sensors for energy studies of below-grade building envelopes and soil heat transfer is discussed. In a two-year study of three basements, heat flux sensors provided valuable information about local variations over the envelope surfaces. For complex building geometries, experimental designs that combine calorimetric monitoring of energy consumption with envelope heat flux profiles from heat flux sensors offer the most efficient means of determining building thermal performance.

The results from heat flux sensors buried in the soil were less satisfactory as the measurements were difficult to interpret because of the variability of soil thermal properties and the sensors' inability to detect vapor transport phenomena. Localized distortions caused by differences between the thermal conductivities of the sensors and their surroundings were found to affect heat flux sensor output significantly.